Which image formats keep transparency — a working map

2026-09-15

A logo with a transparent background goes in; something comes out. Whether the transparency survives depends entirely on the format you chose — and the failure mode is silent: no error, just a white box where the emptiness used to be.

The map

• PNG — keeps it. Full per-pixel transparency. The safe default for logos, cut-outs and stickers.
• WebP — keeps it. Same capability, smaller files; the right choice for images published on your own site.
• SVG — has it going in. Vector sources convert to PNG with their transparency intact.
• JPG — cannot hold it. Transparent areas are filled with white. Not a bug anywhere; the format simply has no concept of a missing pixel.
• BMP and TIFF (as we write them) — filled white. Our encoders write plain opaque images, because the legacy software these formats feed is the least likely to handle alpha correctly.
• GIF (as we write it) — filled white. GIF can technically hold crude one-bit transparency, but a converted still gets a solid background for predictable results.
• PDF — filled white. A page has paper behind it by definition.

In short: keeping transparency means PNG or WebP. Everything else on the list flattens it, and our converter warns you on screen before the flattening conversions run.

The mistake that cannot be undone

Once a transparent image has been saved to JPG, the white is real pixels — no converter can find the old emptiness again. Recovering means either going back to the original file or treating it as a repair job with background removal, which works on plain backgrounds but is a rescue, not a conversion.

What we deliberately don't do

We don't pick a fill colour per image or offer a colour picker for the flattened background. White is what upload forms, printers and viewers expect; a custom backdrop is an editing decision that belongs in an editor.

The short version

• PNG and WebP keep transparency; JPG, GIF, BMP, TIFF and PDF outputs flatten it to white here.
• The tool warns before a flattening conversion — the change is irreversible.
• Flattened by accident? Background removal is the rescue path, original file the better one.